title: Validation of the Elecsys® HIV combi PT assay for screening and reliable early detection of HIV-1 infection in Asia.
abstract: BACKGROUND
  The Elecsys® HIV combi PT assay was developed to allow earlier detection of HIV infection with increased sensitivity and specificity.
  
  
  OBJECTIVE
  To validate the assay for screening and reliable early detection of HIV-1 infection in Asia.
  
  
  METHODS
  Samples tested reflected those routinely screened in Asia and comprised: HIV-1 antigen lysate (25 samples) and antibody (20 samples) dilutions; seven HIV-1 seroconversion panels (46 samples); 39 patient samples from early infection; 183 known-positive sera; HIV-1 p24 antigen sensitivity panel (seven samples); >500 routine clinical samples per center. The Elecsys® HIV combi PT assay was compared with fourth- (ADVIA Centaur® HIV combo, ARCHITECT® HIV combo, Elecsys® HIV combi) and third-generation (VIRONOSTIKA® HIV Uni-Form II Plus O, Zhuhai Livzon Anti-HIV EIA, Serodia® Particle Agglutination) assays commonly used in the region.
  
  
  RESULTS
  Overall, the Elecsys® HIV combi PT showed superior or similar sensitivity to the comparators for detecting all subtypes. The assay correctly identified all positive samples, including those taken soon after infection, and detected seroconversion at a similar or shorter time interval than the comparators. The analytical sensitivity of Elecsys® HIV combi PT for HIV-1 p24 antigen was 0.90 IU/mL, which was lower than reported previously. The assay showed good specificity (99.86%) that was superior or equivalent to the other fourth-generation assays tested.
  
  
  CONCLUSIONS
  These robust data demonstrate the good subtype inclusivity of the Elecsys® HIV combi PT assay and its suitability for screening and reliable early detection of HIV infection in Asia.
authors.affiliation: West China Hospital, Sichuan University, 37 GuoXue Xiang, Chengdu, Sichuan Province 610041, China. taochuanmin@sina.com
authors.forename: Chuan Min
authors.initials: CM
authors.lastname: Tao
authors.forename: Yunjung
authors.initials: Y
authors.lastname: Cho
authors.forename: Kee Peng
authors.initials: KP
authors.lastname: Ng
authors.forename: Xiaoxu
authors.initials: X
authors.lastname: Han
authors.forename: Eun-Jee
authors.initials: EJ
authors.lastname: Oh
authors.forename: Saat
authors.initials: S
authors.lastname: Zainah
authors.forename: Mohd Zain
authors.initials: MZ
authors.lastname: Rozainanee
authors.forename: Lan Lan
authors.initials: LL
authors.lastname: Wang
mesh_terms: D001208:Asia; D019411:Clinical Laboratory Techniques / Q000379:methods*; D042241:Early Diagnosis; D015658:HIV Infections / Q000175:diagnosis*; D015497:HIV-1 / Q000302:isolation & purification*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D012680:Sensitivity and Specificity
keywords: AHI; Ab; Ag; Asia; Assay; Elecsys(®) HIV combi PT; HBs; HIV; IR; N/A; NA; NAT; NIBSC; National Institute for Biological Standards and Control; PCR; RNA; Sensitivity; Specificity; WHO; World Health Organization; acute HIV infection; antibody; antigen; hepatitis B surface; human immunodeficiency virus; initially reactive; not applicable; not available; nucleic acid test; polymerase chain reaction; ribonucleic acid; s/co; signal to cut-off ratio